ACOs season-long CoLABoratory initiative is the first and only professional research and development laboratory to support the creation of cutting-edge new American orchestral music through no-holds-barred experimentation. CoLABoratory alters the landscape by treating the creation of a new orchestral work as an interactive and collaborative process, rather than just the delivery of a musical product. This year, CoLABoratory will include a unique incubation process of workshops, public readings, collaborative feedback, and laboratory performances of music, open to the public, taking place from November 2012 through April 2013.A nationwide call for proposals was submitted last spring for music that challenges conventional notions about orchestral music. The composers selected to participate in the 2012-13 CoLABoratory program will be chosen for their willingness to experiment and stretch their own musical sensibilities, and their ability to test and stretch the possibilities for the orchestra itself. Past participants have created a concerto for junked car and orchestra (Sean Friars Clunker Concerto), collaborations with lighting designers (Laura Schwendingers Shadings), new levels of orchestral improvisation (Henry Threadgills No Gate, No White Trenches, Butterfly Effect), hybrid orchestration of laptop computers and acoustic instruments (Dan Trueman, silicon/carbon (an anti-Concerto Grosso)), and sound paintings for unorthodox spatial arrangements of the orchestra (Joan La Barbaras In solitude this fear is lived). Participating composers will be announced in September 2012.